Door check and closer



June 'J. D. s. LARSSON 2,377,636

DOOR CHECK AND CLOSER Filed Sent. 29, 1942 Patented June 5, 1945 chob'a dimox Aimior iosiin H oohan in iasi' fridgLarsson Eskilstuna, 1

*Appliciiti on september 29, '19'42, "Si:riv'll No.-' l6 337 i In Sweden March 29, 1940 1 Claim.

The present invention refers to a hydraulic door check and closer having a spring adapted to shut the door, the shutting speed being controlled by a hydraulic braking device, and the details of the invention are substantially directed ,to the braking device, the securing of the spring and a simple and reliable means to facilitate the shutting 02E the door by a final impulse. Hereby the door-shutter according to the invention is rendered exceedingly simple, durable, safe in operation and cheap in manufacture.

The invention is illustrated on the accom- .panying drawing, wherein Fig. 1 shows a partly sectioned elevation of the door check and closer case or the door in a vertical position. The

I8 inclined to the axis of the rod. Thus there will be'formed'an opening on the lines of a circular segment in the mouthor the passage 15, the size of which opening is adapted to be minutely controlled by the turning of the screw from the position in which the needle valve is entirely open up to the position in which it is entirely closed. The pressure liquid escapes through said opening in a concentrated jet, which will bring about a soft operation, free from jerks, in the shutting of the door. Arranged about the brake plunger 3 is a powerful helical spring l9 bearing with its lowermost turns in a circular groove 20 in the bottom of the casing so as to be properly uided therein. The upper end 2| of the spring is bent radially inwardly and introduced into. a corresponding transverse recess in the brake plunger, and the lower end 22 of the spring is bent axially downwardly and introduced into a corresponding recess in the bottom of the casing. Alternatively, the end portion 22 of the spring may be bent radially inwardly, a screw being plunger is axially displaceable by the upper portion thereof being provided with threads 6 en- I gaging corresponding threads in the lid. The

bottom portion 1' of the casing is of an enlarged thickness, and provided therein is a tubular cylindrical bore 8 corresponding to the diameter of the plunger, said bore affording adequate guidance to the plunger which reaches the bottom thereof in all positions. The casing 2 is partlyfilled with some pressure liquid 9, such as oil of suitable constant viscosity. The plunger then provided on both sides thereof, so that the heads of the screws are caused to squeeze said end portion securely in position. These means -sition, an overflow passage is formed between the annular space M and the pressure liquid over the bottom of the casing.

The arrangements described operate as follows:

When the door is opened, the brake plunger is turned and at the same time displaced upwardly wardly by atransverse pin L3. The lower porthereto a cylindricalrod l! of the same diameter as that of the mouth of the passage l5 adapted to-receive the end portion of the rod [1. This end portion of the rod is bevelled off on a plane in the cylindrical bore, so that a sucking effect is produced therein, the valve ll being thus opened and pressure liquid flowing into the annular space [4 through the passages Ill and I5,

closed and pressure liquid is forced out through the passage l5, wherein the needle valve controls and brakes the flow, so as to prevent the door from being shut too rapidly. When the door is nearly closed and the recess 213 of the ceases, sov that at the moment of shutting the door the spring only has the air resistance in the doorcase to overcome and the door is thus caused to be shut with a final impact, that is to say more rapidly, with a movement time from resistance during the very last portion of the shutting movement, which involves that the shutting of the door takes place more rapidly than if the plunger were to have a braking effect up to the moment the door was closed.

What I claim is:

A door check'and closer comprising a cylindrical rotatable brake plunger provided with threads on the upper portion thereof in engagement with threads of an aperture in the lid, a helical spring about the brake plunger, the

upper end of the spring being-bent radially intions, an annular space concentric to the brake plunger in the lower portion of the cylindrical bore, an axial recess 'in the brake plunger arran'ged for a distance above the lower end of the brake plunger, the length Of said recess being so adapted that, when the brake plunger is near its lowermost position, an overflow passage is formed between said annular space and the pressure liquid in the casing.

JOHAN DAVID SIGFRID LARSSON. 

